Settling-tank.



K. IMHOFF.

SETTLING TANK.

urmoumn FILED SEPT. 28, 1910.

1,057,154; Patented Mar. 25, 1913.

: To all whom it may concern:

mar. IMHOFF, or BREDENEY, NEAR nssnn-on-rnn-nuna, GERMANY.

- SETTLING-TANK; p

Be it known that I, KARL IMHOFF, a subject of the German Emperor, andresiding at Bredeney, near Essen-on-the-Ruhr, Germany, have inventedcertain new and use ful Improvements in Settling-Tanks, oi

which the following is'a specification.

My invention relates "to settling tanks for i the treatment of sewage.

In the sewage-treatment apparatus described in Letters Patent No.924,664,granted to me heretofore, the decomposing chambers for thesludge are provided below the settling chambers traversed by the wastewater. In all well-known makes of such apparatus for ordinary wastewater the set: tling chambers are smaller than the decomposing chambers-or sludge-basins and are arranged within orearound the latter. It hasbeen found, however, that this construction has various defects and isnot adapted to be used satisfactorily in certain cases.

'A primary object of my invention is to provide a settling tank by whichthese draw. backs are obviated, and to this end I make the settlingchamber much larger than the decomposing chamber or sludge-well. Thesettling chamber cannot then be arranged within the decomposing chamber,but, reversely, the decomposing chamber is arranged as an addition tothe settling chamber. Such an arrangement is necessary when the wastewater is very thin and when but little sludge is deposited, or when itis desired that the sludge shall decompose to only a small extent,that-is when the sludge is to be left in the decomposing chamber foronly a short time.

The settling chamber can be enlarged relatively to the decomposingchamber, when both chambers are made, for example, in the form of wellsor basins, by making the decomposing chamber of smaller diameter andarranging it at the bottom of the settlin chamber.

An illustrative embodiment of my invention is represented by way ofexample in the Specification rimers Patent; Application filed September28, 1910. Serial No. 584,199.

accompanying-drawing, which represents a vertical longitudinal sectionof my improved settling tank. I

The settling chamber is made of larger diameter than the decomposingchamber or sludge-basin and of rectangular shape and PatentedMar.25,1913.

longer or broader than the latter. It is pro- I ,vided with a slopingside, but as this cannot always be made sufliciently steep in all partsfor the sludge to slide downautomatically into the sludge-basin, scraers have to be provided in order .to push t e sludge down from time totime. Such a settling tank isrepresented in the drawing. Thesettling-chamber a is here again located above the sludge-basin 6. Butas the gradient of the slop ng bottom h of the settling-chamher is notsufliciently great, the scraper 21 is provided. The waste water flows inat the upper end of the settling-chamber and out at the-opposite end.-In this arrangement the shortest path for the water 'from the in-' letto the outlet is located through the settling-chamber only and notthrough the sludge-basimso that the sludge is deposited in'thesludge-basin b.

The sludge-basin b is provided with an inwardly-projecting sloping ledgeb and a cone-shaped deflector 03 above the same, the

KARL IIIMHOFF. [11.5.]

Witnesses WALTER VONNEGUT, ALFRED HENKEL.

